An optical device is provided that comprises a multi-order diffractive Fresnel lens (MOD-DFL) and an achromatizing compensation mechanism that reduces refractive dispersion created by the MOD-DFL, thereby reducing the focal range of the MOD-DFL. A method is also provided of using the optical device in an image processing system to obtain images of an object and processing the images to perform image enhancement.

A tunable ultra-compact spectrometer and methods for spectrometry therefor can include a single pixel and a Fresnel zone plate having a focal length at a first temperature T.sub.1 and a first wavelength λ.sub.1, and a focal point. The pixel can be twenty micrometers square and can be placed at a distance from the pixel that equal to the focal length so that the focal point is at the pixel. The Fresnel zone plate can be made of a material that causes the same focal point at the pixel at T.sub.2, but at a different wavelength λ.sub.2 than wavelength λ.sub.1. A heat source can selectively add heat to the Fresnel zone plate to cause a second temperature T.sub.2. Exemplary materials for the Fresnel zone plate can be quartz for visible wavelengths, silicon for infrared wavelength, or other materials, according to the λ(s) of interest.

An image display device according to an aspect of the present technology includes an emission portion, a transparent base material, an irradiation target, and an optical portion. The emission portion emits image light along a predetermined axis. The transparent base material includes a tapered surface having a tapered shape along the predetermined axis. The irradiation target is disposed at at least a part around the predetermined axis along the tapered surface. The optical portion controls an incident angle of the image light on the irradiation target, the image light having been emitted from the emission portion, the optical portion being disposed in a manner that the optical portion faces the emission portion on the basis of the predetermined axis.

According to one embodiment, a display device includes a first arrangement layer and a second arrangement layer. The first layer includes a first pixel, a second pixel, and a third pixel are arranged periodically in one direction. The second layer is opposed to the first layer, and the second layer includes a first element, a second element, and a third element which are arranged periodically to correspond to the first pixel, the second pixel, and the third pixel, respectively, and separate emission light to light of wavelength corresponding to a first color, light of wavelength corresponding to a second color, and light of wavelength corresponding to a third color to be emitted on the first pixel, the second pixel, and the third pixel, respectively.

A focusing device includes a substrate and a plurality of scatterers provided at both sides of the substrate. The scatterers on the both sides of the focusing device may correct geometric aberration, and thus, a field of view (FOV) of the focusing device may be widened.

A wideband diffractive component capable of diffracting an incident beam exhibiting a wavelength lying in a diffraction spectral band, the diffractive component elementary areas arranged on a surface, each area belonging to a type indexed by an index i lying between 1 and n, with n greater than 1, index i corresponding to blaze wavelength λi of index i, the blaze wavelengths lying in the diffraction spectral band, an elementary area of type i comprising microstructures having at least a size less than 1.5 times the blaze wavelength of index i, the microstructures arranged to form an artificial material exhibiting an effective index variation such that an elementary area of type i constitutes a blazed diffractive element at the blaze wavelength λi of index i, the different values of the blaze wavelengths and the proportion of surface area occupied by the areas of a given type a function of a global diffraction efficiency desired in the diffraction spectral band.

A multifocal IOL including at least one diffractive surface including a plurality of discrete, adjacent, diffractive, concentric rings, having a radial phase profile cross-section with a near-symmetrical diffractive surface topography, and an odd number, greater than three, of diffractive orders and an asymmetrical distribution of energy flux over the diffractive orders.

A typical liquid crystal lens includes liquid crystal sandwiched between transparent substrates, which are patterned with ring electrodes. Applying a voltage across the electrodes causes the liquid crystal molecules to rotate, changing their apparent refractive index and the lens's focal length. The ring electrodes are separated by gaps and get narrower toward the lens's periphery. If the ring electrodes are too narrower, their cannot switch the liquid crystal well. To address this problem, an inventive liquid crystal lens includes a substrate with a stepped surface that defines concentric liquid crystal regions with thicknesses that increase with lens radius. Each region is switched by a different set of ring electrodes, which may be on, under, or opposite the stepped surface. Within each region, the ring electrodes get narrower farther from the lens's center. But the ring electrodes' widths also increase with liquid crystal thickness, offsetting the decrease in width that degrades lens performance.

A head mounted display system can include a camera, at least one waveguide, at least one coupling optical element that is configured such that light is coupled into said waveguide and guided therein, and at least one out-coupling element. The at least one out-coupling element can be configured to couple light that is guided within said waveguide out of said waveguide and direct said light to said camera. The at least one coupling element may comprise a diffractive optical element having optical power.

The imaging device includes: a modulator configured to modulate a light intensity in accordance with a real pattern; an image sensor configured to create a sensor image in accordance with the modulated light; and a micro lens array including a plurality of micro lenses arranged to correspond to a plurality of pixels of the image sensor. The imaging device has a distribution property of a relative positional difference amount between a center position of a light receiver of each pixel of the plurality of pixels and a center position of each micro lens of the plurality of micro lenses of the micro lens array in a plane of the image sensor. This property has at least one point or more with a changing difference value of the difference amount between the adjacent pixels from a positive value to a negative value or from a negative value to a positive value.